Electromagnetic wave reflective fabric

Abstract

The present invention is directed to a fabric capable of reflecting electromagnetic waves. The fabric contains metal-coated (preferably aluminum) glass fibers bonded together with sheath-core binder fibers. The glass fibers are typically less than 11/4 inches long and the binder fibers are originally approximately 2 inches long. The glass and binder fibers are thoroughly mixed and spread across a flat surface, such as a conveyor, prior to heating. After heating, the mixture is compressed to form the reflective fabric.

We claim: 
     
       1. An electromagnetic wave reflecting fabric compound comprising: a plurality of metallic fibers for reflecting electromagnetic waves,   a plurality of sheath-core binder fibers dispersed throughout said metallic fibers, said binder fibers having a sheath melted sufficiently to bond said metallic fibers and said sheath-core fibers together,   a molding resin, and   said metallic fibers and said binder fibers form a mat of material capable of reflecting electromagnetic waves, said mat impregnated with said molding resin to form an electromagnetic wave reflective antenna dish.   
     
     
       2. The electromagnetic wave reflecting fabric compound of claim 1 wherein said metallic fibers are glass fibers having a metal coating. 
     
     
       3. The electromagnetic wave reflecting fabric compound of claim 2 wherein said metal-coated glass fibers are coated with a metal selected from the group consisting of aluminum, copper, nickel and stainless steel. 
     
     
       4. The electromagnetic wave reflecting fabric compound of claim 2 wherein said metal-coated glass fibers have an aluminum coating. 
     
     
       5. The electromagnetic wave reflecting fabric compound of claim 1 wherein said binder fibers are selected from the group consisting of polyester, bicomponent polyester and polypropylene. 
     
     
       6. The electromagnetic wave reflecting fabric compound of claim 2 wherein said metal-coated glass fibers are selected from glass consisting of E-glass, C-glass, D-glass and S-glass. 
     
     
       7. The electromagnetic wave reflecting fabric compound of claim 2 wherein said glass fibers are in the range of approximately 8 to 40 microns in diameter. 
     
     
       8. The electromagnetic wave reflecting fabric compound of claim 2 wherein said glass fibers are in the range of approximately 0.75-2.0 inches in length. 
     
     
       9. The electromagnetic wave reflecting fabric compound of claim 1 wherein said binder fibers are in the range of 1.5 to 3.0 inches in length. 
     
     
       10. The electromagnetic wave reflecting fabric compound of claim 1 wherein said binder fibers are approximately two inches in length. 
     
     
       11. The electromagnetic wave reflecting fabric compound of claim 1 wherein said binder fibers are approximately 2 to 4 denier. 
     
     
       12. The electromagnetic wave reflecting fabric compound of claim 1 wherein said sheath of said binder fibers has a melting point lower than said metallic fibers. 
     
     
       13. The electromagnetic wave reflecting fabric compound of claim 1 having approximately 80% metallic fibers with respect to the total weight of metallic fibers and binder fibers exclusive of the molding resin. 
     
     
       14. The electromagnetic wave reflecting fabric compound of claim 1 having between 5 and 80% binder fibers with respect to the total weight of metallic fibers and binder fibers exclusive of the molding resin. 
     
     
       15. The electromagnetic wave reflecting fabric compound of claim 1 having approximately 20% binder fibers with respect to the total weight of metallic fibers and binder fibers exclusive of the molding resin. 
     
     
       16. The electromagnetic wave reflecting fabric compound of claim 1 having a weight of approximately 0.3 to 0.5 ounces per square foot exclusive of the molding resin. 
     
     
       17. The electromagnetic wave reflecting fabric compound of claim 1 having a weight of approximately 0.5 ounces per square foot exclusive of the molding resin. 
     
     
       18. The electromagnetic wave reflecting fabric compound of claim 1 having a thickness of at least 0.02 inches. 
     
     
       19. An electromagnetic wave reflecting fabric compound comprising: a plurality of metallic fibers for reflecting electromagnetic waves,   a plurality of sheath-core binder fibers dispersed throughout said metallic fibers, said binder fibers having a sheath melted sufficiently to bond said metallic fibers and said sheath-core fibers together,   a molding resin, and   said metallic fibers and said binder fibers being cross-lapped and forming a mat of material capable of reflecting electromagnetic waves, said mat impregnated with said molding resin to form an electromagnetic wave reflective structure.   
     
     
       20. A reflective antenna dish comprising: metallic fibers for reflecting electromagnetic waves,   sheath-core binder fibers dispersed throughout said metallic fibers, said binder fibers having a sheath melted sufficiently to bond said metallic fibers and said binder fibers together,   a molding resin, and   said metallic fibers and said binder fibers form a reflective fabric compound of the antenna dish, said mat impregnated with said molding resin to form an electromagnetic wave reflective antenna dish.   
     
     
       21. The reflective antenna dish as claimed in claim 20 wherein said reflective component and said resin form a molding compound for molding into said antenna dish. 
     
     
       22. An electromagnetic wave reflecting fabric formed from the process comprising: mixing metallic fibers and binder fibers;   heating the mixed metal-coated glass fibers and binder fibers until said binder fibers melt;   shaping the mixture of glass fibers and melted binder fibers into a fabric capable of reflecting electromagnetic waves,   impregnating a resin into said fabric to form a molding compound; and   molding the compound into an antenna dish.   
     
     
       23. The fabric formed in claim 22 wherein said metallic fibers are metal-coated glass fibers. 
     
     
       24. The fabric formed in claim 22 wherein said binder fibers are sheath-core binder fibers. 
     
     
       25. An electromagnetic wave reflecting fabric compound formed from the process comprising: mixing metallic fibers and binder fibers;   spreading said mixture evenly over a substantially flat work-surface;   heating the mixed metal-coated glass fibers and binder fibers until said binder fibers melt;   compressing the mixture to ensure proper bonding of the mixture thereby forming a flexible mat capable of reflecting electromagnetic waves   impregnating a resin into said fabric to form a molding compound; and   molding the compound into an antenna dish.   
     
     
       26. The fabric compound formed in claim 25 wherein said metallic fibers are metal-coated glass fibers. 
     
     
       27. The fabric compound formed in claim 25 wherein said binder fibers are sheath-core binder fibers. 
     
     
       28. A sheet molding compound comprising: a plurality of metallic fibers for reflecting electromagnetic waves, a plurality of binder fibers dispersed throughout said metallic fibers, said metallic fibers and binder fibers forming a reflective fabric, and   a resin impregnated in said fabric,   wherein said fabric and resin form a sheet molding compound molded into an electromagnetic wave reflective antenna dish.   
     
     
       29. The sheet molding compound of claim 28 wherein said metallic fibers are metal-coated glass fibers. 
     
     
       30. The sheet molding compound of claim 28 wherein said binder fibers are sheath-core binder fibers.